Does this look right 1985 pinion shaft?
 

Hi

First time posting, long time lurker. Wish I could help out more but I don't know anything. With your guy's help I've been able to fix many things on my old 1985 GMC step side. Thanks.

I decided to open up the rear differential to change the oil and found a surprise waiting for me metal shavings in the fluid. The pinion shaft lock bolt was broken. I was able to order a new one as well as a new cover. I've searched for the correct install for this pin but couldn't find what I was looking for. Does this look right? I can't find a hole in the pinion shaft for the lock bolt Thanks Kyle

Re: Does this look right 1985 pinion shaft?
 

my money pit!

Re: Does this look right 1985 pinion shaft?
 

Sorry to say but that hole should not be oval. Your rear is shot. It needs to be rebuilt or replaced. No way around that :/
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Re: Does this look right 1985 pinion shaft?
 

Well I was hoping for the best and got what I had thought. Didn't think it was possible to wear that much. Most of the pictures i've seen the hole was round and didn't want to believe it had worn that much. This might be the last straw for this truck. Time to start looking for a better side step with AC and less headaches. Thought I had got a good deal paying 1600 bucks for this truck. I guess it was to true to be good. At least the 305 engine is in good condition I should be able to salvage it. Thanks.

Re: Does this look right 1985 pinion shaft?
 

It still is a good deal. You can simply go to a wrecking yard and get a whole new rear. It's like $125 here for me. I've done it and so have a few freinds of mine. When that center pin gets worn it rocks back and forth and wears a grove and often breaks.

Remember these trucks are in thier 20s at least not a lot of easy miles on most. Fixing the wear areas makes a big difference. It's mainly the drivetrain and then the suspension in that order to worry about. Nobody said fixing cars and trucks was easy and that's not really why we do it. Just take the good and bad in stride and it will be there for you always
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Re: Does this look right 1985 pinion shaft?
 

I agree. Don't get rid of the truck because of that. Go to the bone yard and pick up another one or get a new carrier and rebuild it. (or have it rebuilt if your not comfortable with diff's)

Re: Does this look right 1985 pinion shaft?
 

Go to a yard and get another 1/2 ton axle. They're cheap, plentiful, and pretty easy to swap.
Look for one off a truck without a trailer hitch. You can pull the diff cover before you yank it or ask the yard ducks to pull the cover off one they pulled... Just to make sure there aren't any surprises like the one you just got.

Re: Does this look right 1985 pinion shaft?
 

also by pulling the cover you might want to check to have the same ratio, at least if you dont want to change it, to give you less work....

Re: Does this look right 1985 pinion shaft?
 

If you dont want to go that route go to a parts store and buy the spider gears. They have a kit to replace all four spider gears. Usually less than 75 bucks.
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Re: Does this look right 1985 pinion shaft?
 

Yep, as said above, junkyard. Measure your WMS to WMS to be sure you find the correct width when you get to the junkyard. Also, look at the numbers on your existing ring and match those. You should see something like 41 - 11 (3.73 gears) or 41 - 12 (3.42).

Also, just double check the spring perch measurements but they should be the same unless you look at a 1 ton.....

Used axles are $100 here.

Also, pay attention to 5 lug or 6 lug (yours looks like a 2wd)

Re: Does this look right 1985 pinion shaft?
 

That won't work the center pin for the spiders has worn a groove in the carrier. It has to be pulled no matter what.
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Re: Does this look right 1985 pinion shaft?
 

Okay so my options are

1. nothing just put it back together and drive. It was running fine.

2. Can i just replace the carrier? this seems like the easiest route. I wouldn't have to take the axle off?

3. replace the whole axle.

I'm leaning to just putting it back together for now and fix when it's warmer.
should I leave the pinion lock bolt in or take it out? regular 80-90 weight differential fluid okay?

Thanks guys couldn't do it with out all the help.

Kyle

Re: Does this look right 1985 pinion shaft?
 

No replacing just the carrier won't work. It's spaced specifically for a lash and gear depth. If you got one at a wrecking yard you can take it to a shop to be repaired. This may cost more than just buying another axle at the yard.

Putting a new center pin in with those groves means that the entire vehicles weight is on those bolts. They will fail and the spider gears will bind and lock up your wheels. Hopefully in your driveway and not the highway.
I'm surprised it hasn't yet
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Re: Does this look right 1985 pinion shaft?
 

I have detonated rear ends that look a lot better than that. Hard to believe that it hasn't let go yet. I wouldn't drive it. It's just a wrecker ride waiting to happen.

Re: Does this look right 1985 pinion shaft?
 

Agree with all this ^^^^^

The advantage of finding one at a junkyard, the gears are already set up so you don't have to fool with them. To re-do gears, or set up a new carrier means you have to add/subtract shims, re-do your pinion crush sleeve, etc.

Junkyard is your best bang for buck. If it was my truck, I definitely would NOT drive it in it's current condition. I just don't think it's safe. So don't fool yourself it's OK to just put back together and ignore. This is not one of those options.

Re: Does this look right 1985 pinion shaft?
 

Agree there. I've blown up axles in cars and trucks that looked a lot better than that. I've had a couple long rides in a tow truck... One with my brand new 82 Olds Cutlass in tow. Warranty was a wonderful thing there.

Junkyard is definitely the best bang for the buck. The 1/2 ton squarebody axles are very common. If they won't let you look inside go elsewhere.

I did my Dana 44 and 14bolt axles in the 76. They work well and are very quiet but I'll never do another Dana if I can help it. The tooling and parts will cost you more than a decent used axle. If you still feel like a learning experience setup a crush sleeve and side shim pack axle. You won't ever want to do one again.

Some shops are good some are not but they all will cost more than a decent complete used axle. The bad shops will cost much more.